In the past decade, urban dwelling children, Hispanic Puerto Ricans, and African Americans have suffered disproportionately from asthma and many hypotheses regarding lack of access to appropriate care, cultural practices, environmental exposures, or genetically determined pathophysiologic processes individually or in combination have been proposed to underlie the observed demographic characteristics of poorly controlled asthmatics. The genetic predisposition to asthma is well established; however despite,evidence for loci on chromosomes, genes for asthma and its associated phenotypes have not been found. A part of the problem in locating putative susceptibility genes is the complexity of the asthma and asthma related phenotype(s), and the unascertained influence of the environment on these measures. The goal of this proposal is to identify genetic determinants of asthma. Initially, we will examine the alpha 1-Antitrypsin gene. While assocation of alpha 1-Antitrypsin variants with asthma was predominantly reported in Puerto Rican Hispanics, we will examine subjects of African American, Hispanic Puerto Rican and Caucasian ancestry as our clinic population has approximately equal representation of each ethnicity.